Expanadable spinal jack for installation between upper and lower succeeding superior articular processes

ABSTRACT

A spinal jack adapted for installation between first and second vertebral processes, including first and second inter-expandable jack halves arranged between retracted and expanded positions. Each of the jack halves further includes gripping portions adapted for engaging the vertebral processes. A geared mechanism provides for expanding or retracting the jack halves in order to establish a corrected adjusted orientation between the processes.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a divisional of U.S. Ser. No. 17/516,885filed Nov. 2, 2021.

FIELD OF THE INVENTION

The present invention relates generally to spinal jacks for providinginter-vertebral support. More specifically, the present inventionteaches an adjustable spinal jack for installation between superiorarticular processes of upper and lower succeeding vertebrae.

BACKGROUND OF THE INVENTION

Spinal jacks designs are known in the prior art for providing adjustedand secure positioning support between succeeding spinal vertebra. Anexamples of this is depicted in Linares U.S. Pat. No. 8,623,056.

SUMMARY OF THE PRESENT INVENTION

The present invention discloses a spinal jack adapted for installationbetween first and second vertebral processes, including first and secondinter-expandable jack halves arranged between retracted and expandedpositions. Each of the jack halves further includes gripping portionsadapted for engaging the vertebral processes. A geared mechanismprovides for expanding or retracting the jack halves in order toestablish a corrected adjusted orientation between the processes.

In a first variant, a hex key rotatable driver actuates, via a bevelgear arrangement, a pair of laterally expandable slave gears supportedupon a stationary shaft. A pair of extending support stems associatedwith one of the jack halves are provided and include inwardly steppedratchet locations which abut the opposite outward faces of the slavegears in order to adjust a lateral separation between the jack halves.The spinal jack halves are further biased in an outward expandingdirection.

In a second variant, a central body supports the outwardly displaceablespinal jack halves and includes a rotatable worm gear which in turnactuates a disk gear having both outer and inner coaxial arrangedthreads. These in turn mesh with threads configured in support stemsassociated with each of the jack halves and so that, upon actuating theworm gear to drive the disk gear, the spinal jack halves are caused tointer-displace in an outwardly expanding configuration.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference will now be made to the attached drawings, when read incombination with the following detailed description, wherein likereference numerals refer to like parts throughout the several views, andin which:

FIG. 1 is perspective view of a spinal jack according to onenon-limiting variant and having first and second spinal jack halvesshown in a retracted position prior to being installed betweensucceeding superior articular processes associated with upper and lowerconsecutive spinal vertebra;

FIG. 2 is a succeeding illustration to FIG. 1 and depicting the spinaljack in an expanded position and further illustrating an expandablerubberized skirt located between the outwardly inter-displacing jackhalves;

FIG. 3 is a cutaway view taken along line 3-3 of FIG. 1 and showing thepair of slave gears supported upon a width extending shaft in theretracted position;

FIG. 4 is a cutaway view taken along line 4-4 of FIG. 2 and showing theadjusted position of the slave gears relative to the inwardly steppedratchet stems to the outward-most expanded position;

FIG. 5 is a cutaway taken along line 5-5 of FIG. 1 and showing bevelgear arrangement established between the drive gear and slave gearscorresponding to the lowermost retracted position of FIG. 3 ;

FIG. 6 is a perspective view of a spinal jack according to a furthernon-limiting variant and including a central body supports the outwardlydisplaceable spinal jack halves in a retracted position;

FIG. 7 is a further view to FIG. 6 and illustrating the spinal jackhalves in an inter-outward expanded position;

FIG. 8 is a cutaway view taken along line 8-8 of FIG. 6 and illustratingthe rotatable worm gear which in turn actuates a disk gear having bothouter and inner coaxial arranged teeth, these in turn meshing withopposing teeth configured in the support stems associated with each ofthe jack halves; and

FIG. 9 is a corresponding cutaway view to FIG. 8 and depicting thespinal jack halves being caused to inter-displace in the outwardlyexpanding configuration.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to the attached illustrations, the present inventiondiscloses a number of variants of an adjustable spinal jack forinstallation between superior articular processes of upper and lowersucceeding vertebrae. A general representation of a selected jack isdepicted generally at 10 in the perspective view of FIG. 1 and isunderstood to be positioned between upper and lower 4 successivesuperior articular processes (not shown) corresponding to upper andlower vertebrae.

As will be described in further detail with reference to the succeedingembodiments, the present invention provides an expandable spinal jackwhich overcomes many of the disadvantages of the prior art and providesan effective solution for stabilizing and fixing in position a givenorientation established between the succeeding vertebrae. As will befurther described, the spinal jack designs described herein furtherpermit adjustment, at any future time following initial surgicalimplantation, in a minimally invasive fashion and in order to re-adjustthe spatial positioning established between the upper and lower halvesof each variant of the spinal jack, such as in order to compensate andcorrect for downstream vertebral complications following the initialimplantation of the spinal jack.

Referring again to FIG. 1 , the perspective view of the spinal jackaccording to one non-limiting variant includes first 12 and second 14bodies, also hereinafter referred to as spinal jack halves, which areshown in a retracted position prior to being installed betweensucceeding superior articular processes associated with upper and lowerconsecutive spinal vertebra. Each of the spinal jack halves can beconstructed of a suitable medical grade sanitary metal, plastic orcomposite and can incorporate opposite and outwardly facing grippingportions, these as further shown exhibiting a substantially “U” shapewith aligning apertures configured in spaced apart and extending legs(see pairs 16/18 for each of first or upper jack half 12 and further at20/22 for second or lower half 14).

Aligning apertures are further defined by spaced apart pairs of innerperimeter extending edges (at 24/26 for upper gripping portion legs16/18 and at 28/30 for lower gripping portion legs 20/22). Asunderstood, the spaced apart pairs of legs 16/18 and 20/22 of theopposite extending gripping portions are adapted to seat the upper andlower consecutive superior articular processes, The inner “U” shapedsurface profile of each of the gripping portions is further exhibited byany type of textured or ribbed profile (see at inner base surface 32 andinner side surfaces 34/36 for the upper spinal jack gripping portion aswell as inner base surface 38 and inner side surfaces 40/42 for thelower spinal jack gripping portion) the purpose of which is to provideadditional resistive engagement against the facet surfaces of thevertebral processes and.

Also shown are screw type fasteners 44 and 46 (see FIG. 1 ) which, uponpositioning and the gripping portions and drilling through the vertebralprocesses, anchor the spinal jack halves 12/14 to the respectivevertebrae. Alternatively, the gripping portions can be crimped intoengagement with the vertebral processes without the use of separatescrews.

FIG. 2 is a succeeding illustration to FIG. 1 and depicts the spinaljack in an expanded position and further illustrating an expandablerubberized skirt 48 located between the outwardly inter-displacing jackhalves 12/14. Without limitation, the skirt can be constructed of anysuitable flexible and FDA (Food and Drug Administration) approvedmaterial.

As further best shown in the cutaway views of FIGS. 3-4 , the skirt 48is initially wound into a circumferential extending roll (FIG. 3 ) andseated within a likewise circumferentially extending pocket 50 extendingwithin a base circumference of the upper spinal jack half 12. Anopposite end of the skirt is anchored (at 52) to an opposing perimeterend face location of the lower spinal jack half 14 such that, and uponexpanding the jack halves 12/14 as shown in FIG. 4 , the skirt 48unrolls to the position depicted in FIGS. 2-4 in which it provides abarrier between the exterior environment and the inner gear mechanism(to be described below) of the vertebral jack assembly. Additionally,the skirt 48 can be tensioned to the rolled up position of FIG. 3 (suchas through the use of additional torsional springs, bands or the like)in order to maintain a tensioned and taut arrangement of the skirt atany expanded adjusted position established between the jack halves12/14.

A rotatable driver component (see at 53 in FIG. 5 ) is depicted andincludes an integrated hex head or other suitable bit receiving opening(further at 54). The driver component is further seated within a closedrim surface defining aperture 56 (see FIGS. 1, 2 and 5 ) associated withthe first or upper jack half 12. A pair of laterally expandable slavegears 58 and 60 (see again FIGS. 3-5 ) are supported upon a widthsupported shaft 62, this in turn being secured in extending fashionthrough a lower interior projection 64 of the upper jack half 12.

As best shown in FIG. 5 , a bevel gear arrangement is establishedbetween the driver component 53 and the slave gears 58/60. The slavegears 58/60 are stationary and each in turn further includes an interiorand laterally displacing inner component (see at 59/61) which isthreaded and inter-displaceable relative to the outer driving slavegears 58/60. The inner components 59/61 are further seated, as shown,over opposite ends of the stationary shaft 62 between the positions ofFIG. 3 (retracted) and FIG. 4 (expanded).

FIG. 5 best shows bevel engaging tooth 66 (associated with selectedslave gear 58) and corresponding outer bevel tooth 68 (associated withdriver component 53), such that rotation of the hex head driver opening54 (via the inserted bit) results in threaded engagement betweeninterior threads 70 and 72 associated with each of the slave gears 58/60and opposing exterior threaded locations 74 and 76 associated with eachof the inner displacing components 59/61. The inner components 59/61each further define interior channels (see as best shown at 78/80 ineach of FIGS. 3 and 5 ) within which is seated the width supported andstationary shaft 62.

A pair of extending support stems 82 and 84 are associated with one ofthe jack halves, and which is shown in the FIGS. 3-4 cutaway views beinganchored into the lower jack half 14 so that the stems 82/84 (best shownin FIG. 3 ) project upwardly within interior tracks or pockets 86/88defined in the upper jack half 12. Each of the stems 82/84 include anindividual plurality of opposing and progressively inwardly steppedratchet locations (see at 86 for stem 82 and at 88 for stem 84 andwhich, without limitation, can be spaced at any desired incrementaldistance such as 2mm per step) which abut the opposite outward faces ofthe laterally displacing inner components 59/61 and to assist inadjusting a lateral separation between the jack halves. One or moresprings (see first pair 90 and second pair 92) are seated within thepocket shaped tracks or pockets 82/84 so that they arecompressed/obscured in the retracted view of FIG. 3 (these can withoutlimitation seat within upper end recessed locations defined in theratchet stems 82/84).

In use, the inner displacing components 59/61 are depicted in theoutermost displaced locations along the shaft 62 in the retractedposition of FIG. 3 . At this point, the spinal jack 10 is position inrelation to a pair of succeeding superior articular processes and, uponactuating the rotary driving (e.g. hex key) component 53 in a firstselected direction, the inter-threaded relationship with the slave gears58/60 causes the inner components 59/61 to retract inwardly, to thepoint at which it unseats/inwardly clears in succession from eachinwardly facing and opposing pair of progressively inwardly steppedratchet locations 86/88. As each inward facing pair of stepped locationsis cleared, the springs 90/92 progressively and outwardly expand thespinal jack halves 12/14 to each succeeding pair of stepped ratchetlocations, and which can occur up to the last and inwardly-most steppedpair of opposing ratchets as shown in FIG. 4 .

Once the spinal jack halves 12/14 are progressively expanded to thedesired separation distance, the rotary driver component 53 is reverserotated in a second direction to outwardly expand the inner components59/61 in order to engage the desired pair of ratchet. Given the inwardlystepped nature of the ratchets, the desired expansion position betweenthe spinal jack halves is maintained via the shoulder interfaces (see byexample at 94/96) established between each succeeding pair of ratchets86/88 so that, and upon outwardly tightening the inner components 59/61of the slave gears 58/60 at the desired ratchet locations 86/86, theadjoining shoulders 94/96 corresponding to the next inwardly steppedratchet location provide a secure engagement profile and prevent furtherinter expansion of the spinal jack halves 12/14.

Proceeding now to FIG. 6 is a perspective view of a spinal jack isgenerally shown at 100 according to a further non-limiting variant in aretracted position and includes a central body 102 which supports a pairof outwardly displaceable spinal jack halves 104 and 106, each of whichagain including any medical grade metal, plastic or composite material.

The central body 12 (as best shown in the spinal jack expanded positionof FIG. 7 ) depicts a three dimensional modified puck shape with top 108and bottom 110 facing surfaces, against which are seated (in theretracted positions of FIGS. 6 and 8 ) base surfaces 112 and 114associated with gripping portions configured into each of the upper 102and lower 104 jack halves.

Similar to the preceding embodiment 10 of FIG. 1 , the gripping portionseach further exhibit a substantially “U” shape with aligning aperturesconfigured in spaced apart and extending legs (see upper pairs 116/118and 120/122 for each gripping portion associated with the upper 102 andlower 104 spinal jack halves). The aligning apertures are furtherdefined by spaced apart pairs of inner perimeter extending edges (at124/126 for upper spaced apart legs 116/118 and further at 128/130 forlower spaced apart legs 120/122).

With reference again to FIG. 1 , the spaced apart pairs of legs 116/118and 120/122 of the opposite extending gripping portions are adapted toseat the upper and lower consecutive superior articular processes, Theinner “U” shaped surface profile of each of the gripping portions isfurther exhibited by any type of textured or ribbed profile (see atinner base surface 132 and inner side surfaces 134/136 for the uppergripping portion as well as inner base surface 138 and inner sidesurfaces 140/142 for the lower gripping portion) the purpose of which isto provide additional resistive engagement against the facet surfaces ofthe processes. As shown at 44 and 46 in FIG. 1 , any type of screwfasteners can be employed and which, upon pre-positioning the grippingportions and drilling through the processes, anchor the jack halves12/14 to the respective vertebrae. Alternatively, and as previouslystated, the gripping portions can be crimped into engagement with thevertebral processes without the use of separate screws.

FIG. 7 is a further view to FIG. 6 and illustrating the spinal jackhalves 12/14 in an inter-outward expanded position. FIG. 8 furtherprovides a cutaway view taken along line 8-8 of FIG. 6 and illustratingthe rotatable worm gear which in turn actuates a disk gear having bothouter and inner coaxial arranged threads, these in turn meshing withthreads configured in support stems associated with each of the jackhalves. FIG. 9 is a cutaway view similar to FIG. 8 and depicting thespinal jack halves 12/14 being caused to inter-displace in the outwardlyexpanding configuration.

As best shown in FIGS. 8-9 , the central body 102 includes a rotatableworm gear 144 having exterior spiral arrayed teeth 145 and which, inturn, actuates a disk gear 146, this further exhibiting a multi-sidedprofile as depicted in cutaway and having both outer most facing annularthreads or spiral teeth 148, along with each of first 150 and second 152coaxially arranged inner threads or teeth. These in turn mesh withopposing coaxial threads or teeth 154 and 156 (see further as best shownin FIG. 9 ) configured in in each of support stems 158 (lower spinaljack 14) and 160 (upper spinal jack 12) and so that, upon actuating theworm gear 144 to drive the disk gear 146, the spinal jack halves arecaused to inter-displace in an outwardly expanding configuration.

Similar to the first variant, a hex or other bit shaped key insertportion 162 is shown which is seated within a closed rim 164 defining anaccess passageway through the central body 12. Although not shown, thebit portion 162 can be integrated into the worm gear 144 forinter-displacing the spinal jack halves 12/14 in the manner shownbetween FIGS. 8-9 .

Owing further to the inter-engaging geared relationship establishedbetween the worm gear 144, rotatably engaged disk gear 146 and opposingthreaded gears 154/156 associated with the inner support stems 158 and160 of the jack halves 14/12, adjustment of the spinal jack halves isprovided in a secured fashion (such as during either of initialimplantation or in response to a subsequent change in the patient'scondition in which the spinal jack is further adjusted in-situ andwithout removing from the vertebral superior processes). Additionalstructural features can include an inner-most stem 164, shown integratedinto the lower support stem 158 of the lower jack half 106, which seatswithin an aligning inner-most pocket 166 (see FIG. 9 ) defined in theupper support stem 160 of the upper jack half 104 and in use providessecure support to the jack halves in their inter-expanded outerconfiguration of FIGS. 7 and 9 .

Having described my invention, other and additional preferredembodiments will become apparent to those skilled in the art to which itpertains, and without deviating from the scope of the appended claims.The detailed description and drawings are further understood to besupportive of the disclosure, the scope of which being defined by theclaims. While some of the best modes and other embodiments for carryingout the claimed teachings have been described in detail, variousalternative designs and embodiments exist for practicing the disclosuredefined in the appended claims.

The foregoing disclosure is further understood as not intended to limitthe present disclosure to the precise forms or particular fields of usedisclosed. As such, it is contemplated that various alternateembodiments and/or modifications to the present disclosure, whetherexplicitly described or implied herein, are possible in light of thedisclosure. Having thus described embodiments of the present disclosure,a person of ordinary skill in the art will recognize that changes may bemade in form and detail without departing from the scope of the presentdisclosure. Thus, the present disclosure is limited only by the claims.

In the foregoing specification, the disclosure has been described withreference to specific embodiments. However, as one skilled in the artwill appreciate, various embodiments disclosed herein can be modified orotherwise implemented in various other ways without departing from thespirit and scope of the disclosure. Accordingly, this description is tobe considered as illustrative and is for the purpose of teaching thoseskilled in the art the manner of making and using various embodiments ofthe disclosure. It is to be understood that the forms of disclosureherein shown and described are to be taken as representativeembodiments. Equivalent elements, materials, processes or steps may besubstituted for those representatively illustrated and described herein.Moreover, certain features of the disclosure may be utilizedindependently of the use of other features, all as would be apparent toone skilled in the art after having the benefit of this description ofthe disclosure. Expressions such as “including”, “comprising”,“incorporating”, “consisting of”, “have”, “is” used to describe andclaim the present disclosure are intended to be construed in anon-exclusive manner, namely allowing for items, components or elementsnot explicitly described also to be present. Reference to the singularis also to be construed to relate to the plural.

Further, various embodiments disclosed herein are to be taken in theillustrative and explanatory sense, and should in no way be construed aslimiting of the present disclosure. All joinder references (e.g.,attached, affixed, coupled, connected, and the like) are only used toaid the reader's understanding of the present disclosure, and may notcreate limitations, particularly as to the position, orientation, or useof the systems and/or methods disclosed herein. Therefore, joinderreferences, if any, are to be construed broadly. Moreover, such joinderreferences do not necessarily infer that two elements are directlyconnected to each other.

Additionally, all numerical terms, such as, but not limited to, “first”,“second”, “third”, “primary”, “secondary”, “main” or any other ordinaryand/or numerical terms, should also be taken only as identifiers, toassist the reader's understanding of the various elements, embodiments,variations and/or modifications of the present disclosure, and may notcreate any limitations, particularly as to the order, or preference, ofany element, embodiment, variation and/or modification relative to, orover, another element, embodiment, variation and/or modification.

It will also be appreciated that one or more of the elements depicted inthe drawings/figures can also be implemented in a more separated orintegrated manner, or even removed or rendered as inoperable in certaincases, as is useful in accordance with a particular application.Additionally, any signal hatches in the drawings/figures should beconsidered only as exemplary, and not limiting, unless otherwisespecifically specified.

1. A spinal jack adapted for installation between first and secondvertebral processes, comprising: a central body supporting first andsecond inter-expandable jack halves between retracted and expandedpositions; each of said jack halves defining upper and lower bodies andfurther including gripping portions adapted for engaging the vertebralprocesses; a geared mechanism provided for expanding or retracting thejack halves in order to establish a corrected adjusted orientationbetween the processes; and said geared mechanism including a rotatablydriven worm gear incorporated into said central body which actuates adisk gear, in turn driving gear threads configured into each of firstand second stems supporting said jack halves to define an adjustedseparation distance between said bodies.
 2. The spinal jack of claim 1,said disk gear further comprising a multi-sided profile having bothouter most facing threads, along with each of first and second coaxiallyarranged inner threads meshing with said gear threads in said first andsecond stems.
 3. The spinal jack of claim 1, further comprising a hex orother bit shaped key insert portion integrated into said worm gear andwhich is seated within a closed rim defining an access passagewaythrough said central body.
 4. The spinal jack of claim 1, furthercomprising an inner-most stem integrated into a lower of said jackhalves which seats within an aligning inner-most pocket defined in anupper of said jack halves.
 5. The spinal jack as described in claim 1,said gripping portions each further comprising a pocket adapted toreceive the vertebral process there between.
 6. The spinal jack of claim5, said pockets each further including textured surfaces for providingadditional gripping of the vertebral processes.
 7. The spinal jack ofclaim 1, further comprising each of said upper and lower bodies furthercomprising any medical grade sanitary metal, plastic or compositematerial.
 8. The spinal jack of claim 1, each of said gripping portionsfurther comprising a substantially “U” shape with aligning aperturesconfigured in spaced apart and extending legs for receiving screwfasteners for securing said gripping portions to the vertebralprocessses.